Composition lath board



Aug., 11, 1925.

' G. A. BUTTRESS COMPOSITION LATH BOARD Filed Nov. 5, '1923 L? 1 mi m gwouifol gfeufrfss;

To alt 'whom t may concern.'

Patented Aug'. i1, 1925..r

UNITED-germes;

PATENT oFFicE..

cuencas. au'rrarssorms menus, censuarie.

' "'conrosrrioir Laura Bom.

' Appleman med, Novembre; s, ma, l sei-n1 ne. 672,730.,

Be it known that I, GEonen'A. BU'i'iREss, a citizenv of the United. States, residing at Los Angeles, in th'e county of Los Angelesv l and State of California, have invented new land useful'Improvements in Composition La'thv Board, of vwhich the following is4 a specification. l s This invention relates to composition lath and wall boards, and particularly pertains to that class of composition boards which sides. covered, at least in .part,-with .facing embodies a layer of plastic 'or cementitiousv material-in panel formhaving its opposite sheets, and which board also embodies la means for effecting a bond with a surface coating of .plaster or cementitious material. The plastic composition employed in forming the board -is ordinarily made of gypsum, that is, plaster of Paris, or a similar product, combined with other materials,

which, in the formation ofthe board, are

`material such as woven fabric or .latter being more generally used ecause of mixed with water to form a paste that is spreadin.- a la er, which, when dry or'set, constitutes a p aster body or panel to which the facing sheets are usually applied in the course of formation ofthe board.

The facing'sheets are formed of fibrous aper, the

its chea ness. ,Where aper facing sheets are emp oyed, various inds oi'. grades of aper have been used according to particuar requirements; iii some instances ordinary pulp board being used, and in othell casesv 'a paper is empl .ed `which has been rendered .waterproo or water-resistant by satiirating .or c oating with a practically umoisture-impervious substance, such-. as tar,-

asphaltum, parafine or kindred products.- In other instances a paper is employed,

' which, while not being impervious to moisture, is not readil abso tive in quality,

the facing Sheet, as Shown in United sai-,es

Letters Patent No. 1,449,728, issued March such composition lath oard are suitable for use in connection with plasters embodying a gypsum or plaster of Paris constituent, such asp rior wal surfaces, theyare not suitable for use to receive coating of cementitious materials such as aremade from hydraulic ce-` ments as `employed in exterior wall surfaces.

It has been found in ractice that while lasters that are employed on inte- In Vtlie'case of plaster, the wetplastic mass l quickly sets whenspread on the wall `surfaces and accordinglyl ordinarily readily adheres to a paper surface, evenwhen the pa er be of oily character, aswhen treated with ywaterproofing materials., But inl-the case of cement, the wet plastic mass is so slow in setting that it will notreadily `adhere' to a paper surface, and accordingly rolls up under the trvowel when'applied -to such a surface and pulls-'away from the paper,

particularly when the paper is of oily nature.; and furthermore, even after the expendture of muchtime and labor the cement is caused to remain in`place, which is'ordinarily facilitated bythe use of wire reinforcements arranged over the surface of the lath board, the cement when set will frequently pull'away from the aper of the lathboard `due to the lack of a hesion so that the lath board does notY serve to su port the cement coating, and results in te formation of fissures or cracks in the'cement coating.

The object of the presentinvention is to provide a composition lath board embodying a` composition nel having a paper facin sheet, in whic r the facin sheet is coate with a substanceiwhich will act to effect a bond between the facing sheet and a cement or plaster coating applied thereto, whereby the coating will be caused to readily adhere to the. facing'shet until'it has set and to effect such an adhesion between the coating and the board as to form a permanent bond afterthe cement or| plaster has set.

A further object is to provide a coating for composition lath boards which, while serving to yefiect'adhesion between the cement or plaster and a paper. surface, will also serveas a coating for exposed areas of the composition body of the board so as to neutralize to a degree .the excessive' absorptiveness' of such exposed areas.l

. vention resides in the construction and in thernethod hereinafter set forth and which is illustrated in the accompanying drawings,

. in whicli- Figure 1 is a perspectiveview of a frag.-

ment of a composition lath and wall board as constructed in accordance with the. present invention. A

Figure 2 is a detail in section vas Vseen'on theY line 2-2of Figure .1, showing the lath and .wall board with a surface coating asY applied thereto-and forming a wall surface. Figure 3 is a detail in section onthe line 33 of Figure-'2.-

More specifically, .3 indicates lbody of .plastic material which is formed into a panel and is covered on one side by a backing sheet.

4.of paper or other suitable sheet material,

is covered on Aits other side by a facing sheetj preferably formed of' water-proofed orsemi-waterproofed fibrous material.

of perforations or apertures `'which 'are' The facing'sheet 5 is formed with a series preferably elongated and arranged iii-rows with the apertures 1n one row in staggered relation to the apertures in theadj acent r'ow.

Into thes'evaperturesthe plastic .compositionof which the` body 3 consists projectsto form Y exposed areas of the com osition bodyat.. intervals. throughoutthej acinguslieet, the

surface of which exposed-areas lie oiia plane substantially fiushlwith vthe outer surface of the facing sheet, and are f roughened or scratched to provide' a surface having irregllv` lar projections or protuberances 8 which -will aid-the adhesion to the .plastic body 3 of .a

coatin 9 of plaster orcementappliedto the face o the board.-

In carrying ollt'the present-invention the facing sheet 5' andthe exposed roughened Surface effihaeomposiuon body e which project throughthe aperturesf, are covered with 'a coatlO of adhesive'niaterial.. This adhesive materialmay be of any suitable nature and may consist, for example -ofa mixtureof glue and dextrine, which has been found 'to be verysuccessful in commercial f practice; The adhesive material preferably employed comprises `a mixture of. lue and dextrine `which is prepared by dissolving dextrine in'iater and adding .thereto ."glue f meltedin water. The proportions fof. the ingredients preferably employed .are z tbpf1-1tV onsof water, seventy-live poundsspf .Y

' that the .board will dextrine, 'and twenty-five pounds of glu'.-1i

This liquid adhesive materialI maybe ap- .Hashem 'Placed' .in a' wall iustipieviousiw the; application of the surface coat 9i'of. plaster 55' o r cement tothe same'. If the former..pr.0

cedure has been follwed, the adhesive' material will be dry when the plaster is .ap` plied, but will be moistenod bythe water of thev plaster or cement so that it will become stickyand readilyadhere-to the surface coat.

The adhesive mixture of glue and dextrine with the permanent adhesion of the cement;V

By thus processing the plaster or cementreceiving face of the lath boardv I am enabled to employ a facing sheet on the latter.

which has been treated with tar, as haltum, paraffin and the like without detracting from the utility ofthe board as a`1ath.

In forminga wall'surface the composition lath and vboard comprising the composition body 3 covered with facing sheets 4 and 5, is applied to asuitable'jbacking or su port, such as a frame work,'as is common inb ing construction; the' adhesive coating l0 being applied to the facing sheet in any suitable manner either beforeV or after the lath board has been mounted to form the walls. The surface coating 9, comprising the usual -wet plastic. mixture of'materials of which plaster or cement is commonl made, includ- -in the usual manner. V'The moisture of the wet fmixture serves to soften the adhesive coating l0 and. acts to render the latter sticly so that the plaster mixture will readily here thereto andzbeso. held in'place throughout the surface of the lath board as not to water constituent, ist en appliedin roughened, exposed areas 7 serving further 5 .toghold the coating 9 in place. Further'- more, 'then wettingof' the portions of the adhesive coatin Y ying -over the roughe'ned areas will, y reason of the inherent absorptive quali of the composition 3, cause to assist in holding the plaster coating `9 in place on the/face of lthe latli'f board, and yet prevent toov rapid absorption Vof moissuchsuction-lt ou hout-the exposed areas` ture from the `wet .plastic coating 9 .by the Y exposed portions of the composition body 3. When the-. coating `Qbecol'iies or set the adhesiver coatin willalso dry an .set so'that the coat 9 will-gemme rmly adhered to the facing sheetas Well as to theroughened surthe coat9. y J In some instances reinforcing wires 'are lplaced in-front-of the -lath-board -to l-tliefload of the .facing .coat 9,but

.I- claim i face oftheexposedareas 7 of the board, soV

vserve as a support for t' forms'no partofftlie present'invention. 136

panel, a facing sheet thereon, and a coating of adhesive material on said facing sheet which is hard when dry but becomes sticky when moistened.

2. A.' composition lath and Wall board comprising a panel of absorptive material, a backing sheet covering one side of said panel, a facing sheet extending-over the other side of said panel; said facing sheet being formed with a'series of apertures into which portions of the plastic composition project and terminate substantially flush with the outer surface of the facing sheet; the surface of the plastic material being exposed through said apertures and having irregular projections of the absorptive plastic material protruding therefrom forming bonding keys thoughout said exposed surfaces, and a coating of adhesive material on said facing sheet and on the exposed surfaces of said plastic material.

3. A composition lath and Wall board com prising a panel of plastic material, abackingsheet covering one side of said panelv and a facing, sheet extending over the other side of said panel, said facing sheet being formed with a series of aperturesand the plastic body formed with portions projecting into said apertures and terminating substantially flush with the outer surface of the facing 'sheet' forming exposed areas of plastic'material throughout the panel, said exposed areas "being roughened, and a coating of adhesive material on said facing sheet and on said exposed areas of said plastic material said adhesive material being adapted to become sticky when moistened.

4f. A composition lath and Wall board comprising a panel of absorptive plastic material, a backin sheet covering one sideof said panel, an a facing sheet extendin over the other side of said' panel; said acingV sheet being formed with a series of.

apertures into which portions of the plas# tic composition project and terminate substantially flush with the outer surface of the facing sheet; the surface of the plastic material being exposed 'through said apertures and having irregular projections of the absorptive plastic material-protruding Hush with theouter surface of thefacing.

ysheet` forming exposed areas of plastic mate- 'ial throughout the panel, said exposed areas being roughened, and a coating of glue and dextrine on said facin sheet and on said exposed areas of said pastic material.

GEORGE AQBUTTRESS. 

